I use 4.30's and run the 30 x 9 Hoosier radial slicks. I drive to the track on them and race on them. I turn about 3200 at 60 mph and dive it the 90 miles to Carlisle like that on Rt 83 and the PA Turnbike. I use a 9.5 Dynamic street/strip converter. It does not bother me at all on the highway as most cars ran 3.91's or more gear when I was a kid in the 60's as I remember riding in a friends brothers 69 Cuda 383 with 3.91's and short street tires about 25 or 26" tall. It seemed like he was turning 4000 rpm at 60 mph(just a guess as I was 14 when riding in it)and it seemed everyone with a hotrod or muscle car ran alot of gear and still ran the highway. So I guess thats why 3200 rpm at 60 dont bother me. In fact it sounds like the eng is just purring along at that rpm. Ron